week3.md

 home | syllabus | src | submit | chat | ©2019 by Tim Menzies

Review, week3

Things to know

• "CoffeeScript is a transpiler language." Explain.

• List 2 advantages and disadvantages of writing languages using the following. For each item write at least 5 lines describe the thing before talking of its advantages and disadvantages

  • precedence-drive grammars
  • interpreters in Prolog
  • macros
  • transpilers

• LLVM: what are two examples (each) for the following LLVM passes. For each example, describe what it is and why it might be useful

  • analysis
  • transformations
  • utilities

• If I set any of the Smalltalk homework questions, could you answer them in an exam?

• Write a Smalltalk object method for collecting every second item in a Collection.

  • Should that method be in Collection? Discuss.

• The following question using the Smalltalk hierarchy, described below:

  • Define a String method for testing if a String is a palindrome (i.e. you get the same string if you write it backwards and forwards).
  • Discuss the merits, if any of moving that method down into Symbol.
  • Discuss the merits, if any of moving that method down to Bag.
  • Discuss the merits, if any of moving that method down to Collection.
  • Overall, where do you think that method should live?

Object
    Behavior
      ClassDescription
        Class -- and Class is instance of Metaclass
        Metaclass
    BlockClosure -- []
    Boolean
      False -- false
      True  -- true
    CObject
      -- C stuff
    Collection
      Bag
      MappedCollection
      SequenceableCollection
        ArrayedCollection
          Array
          Interval
          CharacterArray
            String
              Symbol
        LinkedList
          Semaphore
        OrderedCollection
          SortedCollection
      HashedCollection
        Dictionary
          IdentityDictionary
          RootNamespace
            SystemDictionary -- Smalltalk
        Set
          IdentitySet
    File
      Directory
    Magnitude
      Association
      Character
      Date
      Number
        Float
        Fraction
        Integer
          SmallInteger
      Time
    Message
      DirectedMessage
    Point
    Rectangle
    Signal -- exception handling. see on:do:
      Exception
        Error
          Halt
            ArithmeticError
              ZeroDivide
            MessageNotUnderstood
          UserBreak
        Notification
          Warning
    Stream
      PositionableStream
        ReadStream
        WriteStream
          ReadWriteStream -- why not under ReadStream?
            ByteStream
              FileStream
      Random
    UndefinedObject -- nil